In recent years, there have been proposed and developed various engine start control technologies. One such engine start control device, having an engine self-starting function, has been disclosed in Japanese Patent Provisional Publication No. 2002-39038 (hereinafter is referred to as “JP2002-39038”). The engine start control device disclosed in JP2002-39038 includes an in-cylinder direct fuel-injection system provided to spray fuel directly into each individual engine cylinder, a crank angle sensor or a crankshaft position sensor that detects a crank angle of an engine crankshaft, an electronic ignition system that provides high-voltage surges or electric sparks that ignite the compressed air/fuel mixture in the engine cylinders, and an engine start control system that detects or discriminates an engine cylinder (hereinafter is referred to as “#1 cylinder”), whose piston stroke is an expansion stroke, after the engine has been temporarily stopped, and thereafter initiates self-restarting operation or self-start-up operation by spraying fuel into the #1 cylinder in the expansion stroke and igniting the air/fuel mixture in the #1 cylinder, without using an engine starter. In the engine start control device disclosed in JP2002-39038, in order for the self-restarting operation (or the self-start-up operation) to be executed satisfactorily, and thus to enhance the engine self-startablity, an open-and-closure timing of an intake valve of an engine cylinder (hereinafter is referred to as “#3 cylinder”) in a compression stroke is controlled to open the intake valve even on the compression stroke by a variable phase control mechanism. Thus, during the self-restarting operation, it is possible to effectively reduce a compressive force (compression pressure) created by the #3 cylinder in the compression stroke, which compressive force acts to consume part of torque created by the #1 cylinder in the expansion stroke.
Another type of engine start control device has been disclosed in Japanese Patent Provisional Publication No. 2002-61522 (hereinafter is referred to as “JP2002-61522”). In the engine start control device (or the electronic engine control device) disclosed in JP2002-61522, when the engine is shifting to a stopped state, in order to reduce an in-cylinder pressure for easy engine restarting, an intake valve closure timing is, beforehand, phase-advanced to a given timing value before a bottom dead center (B.D.C.) position of a piston by means of a variable phase control mechanism.